Liquid handling apparatus with pump means having mount and seal



1968 J. R. EISENBRAND ETAL 3,370,603

LIQUID HANDLING APPARATUS WITH PUMP MEANS HAVING MOUNT AND SEAL FiledAug. 12, 1966 34 z/enZor 57 JckEEZsenfiraiaQ Qibrt Z15 rga,

United States Patent 3,370,608 LIQUID HANDLING APPARATUS WITH PUMP MEANSHAVING MOUNT AND SEAL Jack R. Eisenbrand, North St. Paul, and Albert T.Braga, West St. Raul, Minn, assignors to Whirlpool Corporation, acorporation of Delaware Filed Aug. 12, 1966, Ser. No. 572,033 9 Claims.(Cl. 137565) This invention relates to liquid handling apparatus and inparticular to means for sealingly mounting a pump in a liquid holderwall.

In one form of liquid handling apparatus such as a dishwasher, a pump ismounted in the bottom wall of the tub such as for use in forciblycirculating the dishwashing water through the dishwashing space. It isdesirable to mount such pump means in such a manner as to avoidtransmission of vibration from the pump to the dishwasher tub for quietoperation of the dishwasher and for improved long life of the apparatus.Further, it is desirable to provide means for sealing the pump apparatusto the tub wall, whereby the pump may be a submersible type disposed inthe sump portion of the dishwasher tub while the associated motor fordriving the pump may be disposed exteriorly thereof. The presentinvention comprehends an improved liquid handling apparatus of this typewherein new and improved means for sealing the apparatus to the sidewall of the liquid holding means are provided.

Thus, a principal feature of the invention is the provision of a new andimproved liquid handling apparatus.

Another feature of the invention is the provision of such a liquidhandling apparatus having new and improved means for sealing a pumpthereof to the wall of the liquid holding means effectively minimizingvibration transmission therebetween.

A further feature of the invention is the provision of such a liquidhandling apparatus wherein the sealing means is extremely simple andeconomical of construction.

Still another feature of the invention is the provision of such a liquidhandling apparatus wherein the need for fasteners and adhesives iseliminated.

A still further feature of the invention is the provision of such aliquid handling apparatus wherein the sealing means is arranged to bereadily installed and removed when desired for facilitated installationand removal of the liquid handling apparatus.

Another feature of the invention is the provision of such a liquidhandling apparatus including liquid holding means having a side walldefining a liquid holding space and means defining a bottom opening,liquid transfer means having a submersible pump disposed in the spaceand a motor for driving the pump extending downwardly through theopening, and means for sealing the liquid transfer means to the sidewall including flange means on the liquid transfer means having an outeredge extending closely adjacent but spaced from the side wall, aresilient seal member having an inner gripper portion sealingly fittedon the flange edge and an outer hollow sealing portion compressedsealingly against the side wall, the seal member having outercircumferentially extending ribs frictionally engaging the side wall anddeveloping therebetween relatively high contact pressure from relativelylow stress forces developed in the hollow outer portion of thecompressed seal member thereby to maintain the sealing engagementagainst vibration forces generated by operation of the liquid transfermeans.

Other features and advantages of the invention will be apparent from thefollowing description taken in con nection with the accompanyingdrawings wherein:

FIGURE 1 is a fragmentary front elevation of a liquid handling apparatusembodying the invention, with portions thereof broken away forfacilitating illustration of the invention;

FIGURE 2 is a fragmentary enlarged vertical diametric section thereof;

FIGURE 3 is a fragmentary horizontal section taken substantially alongthe line 3-3 of FIGURE 2;

FIGURE 4 is a fragmentary enlarged vertical section taken substantiallyalong the line 44 of FIGURE 3; and

FIGURE 5 is a vertical radial section of the seal member prior toinstallation in the liquid handling apparatus.

In the exemplary embodiment of the invention as disclosed in thedrawing, a liquid handling apparatus generally designated 10 is shown tocomprise a dishwashing apparatus having a tub 11 including a lowerannular side wall 12 defining a sump space 13 at the bottom of thedishwashing space 14. As shown in FIGURE 1, the liquid handlingapparatus 10 includes a pump 15 and a rotatable impeller 16 each drivenby a suitable electric motor 17.

As shown in FIGURE 2, the pump 15 extends upwardly from a transversemounting plate 18, and the motor 17 extends downwardly therefrom throughan opening 19 in an inturned lower end 20 of the tub wall portion 12.The mounting plate includes an annular outer edge flange 21. A pluralityof bosses 22 depend from flange edge portion 21 at spaced intervals forcarrying suitable resilient s'pool connectors 23 adapted to engagebottom wall portion 20 in corresponding semicircular recesses 24thereof. As shown in FIGURE 2, the spools 23 may be retained on thebosses 22 by suitable screws 25 and washers 26.

As indicated briefly above, the invention comprehends the provision inapparatus 10 of an improved means for sealing the liquid handlingapparatus defined by the pump 15 and motor 17 to the side wall 12. Morespecifically, as shown in FIGURE 2, the sealing means comprises anannular seal member 27 having an inner gripper portion 28 sealinglyfitted on the edge flange 21 of the mounting plate 18, and an annularhollow sealing portion 29 sealingly compressed against the side wall 12.The seal member 27 is formed of a resilient material, such as extrudedsynthetic rubber. As shown in FIGURE 4, the hollow portion 29 may bejoined to the gripper portion 28 by an integral connecting portion 30.The seal member may be extruded as a continuous length element which maybe cut to suitable size and formed into the annular arrangement thereofby adhesively joining the opposite ends of the cut length as at 31.

The cross-sectional shape of the seal member is best seen in FIGURE 5.As shown therein, the gripper portion 28 includes a relatively thickbase section 32 having an upper inwardly extending flange 33 and a lowerinwardly extending flange 34. The lower surface 33a of the upper flange33, and the upper surface 34a of the lower flange 34 are inclined toconverge inwardly with the minimum spacing between the surfaces 33a and34a being less than the thickness of the mounting plate flange portion21 so that when the gripper portion 28 is mounted thereon as shown inFIGURE 4 the flanges 33 and 34 seal- 3 ingly, snugly embrace themounting plate edge 21. The base section 32 of the gripper portion 28 isfurther provided with an annular, radially inwardly projecting rib 35sealingly engaging the radially outer cylindrical surface 36 of theflange 21. For facilitated flexure of the flanges 33 and 34 of thegripper portion 28 radially inwardly opening annular recesses 37 and 38may be provided in the base section 32 adjacent the flanges 33 and 34,respectively.

The hollow outer sealing portion 29 of the seal member is provided withan outer surface 39 which is substantially circular in cross-section asshown in FIGURE 5. The interior of the sealing portion 29 is defined byan upper surface 40 which is circular in cross-section and centered on afirst axis 41, and a lower surface 42 which is circular in cross-sectionand centered on a second axis 43 slightly above axis 41. The curvatureof the surfaces 40 and 42 may be similar, but by virtue of thedisplacement of the axes thereof, the upper portion 44 of the sealportion 29 is thicker than the lower portion 45 thereof. As shown inFIGURE 5, the 'outer surface 39 is centered on axis 43 and, thus, thethickness of the lower portion 45 is substantially constant throughoutits length.

The interior space 46 within sealing portion 29 is vented through anopening 49 which opens downwardly through the bottom portion 45. Thus,as shown in FIGURE 4, the sealing portion 29 is readily compressiblebetween the gripper base section 32 and the tub wall 12.

To effectively seal the sealing portion 29 to the tub wall, as a resultof the relatively low stress forces developed in the sealing portion 29by the compression thereof, a plurality of ribs 48 are provided on theouter surface 39 at lower portion 45. The ribs 48 extendcircumferentially the length of the sealing portion 29 and therebydefine a plurality of high pressure, line contact sealing engagements ofthe seal portion with the tub wall, as shown in FIGURE 4. As furthershown in FIGURE 4', the compression of the sealing portion 29effectively folds the sealing portion slightly back on itself to haveengagement with the base section 32 spaced from the connecting portion30. Thus, a unique radially outward force is generated by thecompression of the sealing portion 29 I to effect a vibration-proofmaintained sealing of the ribs 48 with the tub wall 12.

As the tub wall 12 becomes constricted to define the inturned flange 20below the seal member 27, any downward movement of the assembly as byyielding of the spools 23, is resisted with increasing force by the sealmember 27 as the sealing portion 29 will wedge tightly between the basesection 32 and the more constricted subjacent portions of the tub wall12. Conversely, if it is desired to removethe assembly from theapparatus 10, the seal member 27 permits ready upward displacementthereof relative to the tub wall as the sealing engagement is effectedby solely mechanical means without the need for fasteners or adhesivesbetween the seal member and the tub wall Still further, if it is desiredto replace the seal member at any time, the seal member may be removedfrom the flange edge 21 by slight deformation of either of the flanges33 or 34 and subsequent axial displacement. Thus, again by virtue of theelimination of any fastening means or adhesives between the seal memherand the flange edge 21, facilitated removal and installation may beeasily effected.

Further, as the seal is mounted on the pump and motor assembly,maintenance thereof is effectively facilitated as compared to theconventional constructions wherein the sealing means is mounted on thetub wall. Still fur- V ther, the seal member 27 provides an automaticself-centering of the pump and motor assembly relative to the tub wallso that equalized sealing forces may be provided along the entirecircumferential length of the sealing ribs. As the seal member providesan effective positioning of the pump assembly during installation, theself-centering action may be permitted to locate the pump and motorassembly with subsequent final support of the assembly by the spools 23being thusly permitted in the centered position. Further, if the spoolmounting means should fail, the seal nevertheless maintains the assemblysupported on the tub wall and effectively maintains its sealing actionto prevent leakage of dishwashing liquid onto the motor at all times.

While we have shown and described one embodiment of our invention, it isto be understood that it is capable of many modifications. Changes,therefore, in the construction and arrangement may be made withoutdeparting from the spirit and scope of the invention as defined in theappended claims.

The embodiment of the invention in which an exclusive property orprivilege is claimed is defined as follows:

1. Liquid handling apparatus comprising:

liquid holding means having a side wall defining a liquid holding spaceand means defining a bottom opening;

liquid transfer means having a submersible pump disposed in said spaceand a motor for driving said pump extending downwardly through saidopening; and

means for sealing said liquid transfer means to said side wall includingflange means on said liquid transfer means having an outer edgeextending closely adjacent but spaced from said side wall, a resilientseal member having an inner gripper portion sealingly fitted on saidflange edge and an outer hollow sealing portion compressed sealinglyagainst said side wall, said seal member having outer circumferentiallyextending ribs frictionally engaging said side wall and developingtherebetween relatively high contact pressure from relatively low stressforces developed in said hollow outer portion of the compressed sealmember thereby to maintain the sealing engagement against vibrationforces generated by operation of the liquid transfer means.

2. The liquid handling apparatus of claim 1 wherein said hollow outerportion of the seal member opens downwardly.

3. The liquid handling apparatus of claim 1 wherein said hollow outerportion of the seal member is provided with an opening for venting theinterior of said hollow seal member portion to the ambient atmospherethrough said bottom opening'of the liquid holding means.

4. The liquid handling apparatus of claim 1 wherein said outer portionof the seal member includes a bottom section and at least one rib isprovided in said bottom section.

5. The liquid handling apparatus of claim 1 wherein said side wall isprovided with a constricted lower end extending below said outer portionof the seal member.

6. The liquid handling apparatus of claim 1 wherein said side wall isprovided with an inturned flange below said seal member and having aninner edge defining said bottom opening of the side wall, the diameterof said inner edge being less than the inside diameter of said sealmember.

7. The liquid handling apparatus of claim 1 wherein said hollow outerportion of the seal member has an upper portion and a lower portion, thethickness -of the upper portion being greater than the thickness of thelower portion.

8. The liquid handling apparatus of claim 1 wherein said seal memberincludes a flexible connecting portion between said gripper portion andsaid hollow outer portion maintaining confronting portions of thegripper portion and the compressed hollow outer portion spaced apart.

9. The liquid handling apparatus of claim 1 wherein the gripper portionsof the seal member is provided with an inwardly extendingcircumferential rib sealingly engaging said outer edge of said flangemeans.

(References on following page) 5 6 References Cited 2,965,112 12/1960Getshell et a1. 134176 UNITED STATES PATENTS 3,263,311 8/1966 La Flame134-176 X Knight 277 178 377 4 0 7/122; ci lt ggtig Danner 277-208 X 5 IHusted 277 178 X ROBERT B. REEVES, Primary Examiner. Hoilerith 137565 N.L. LEIMER, Assistant Examiner.

1. LIQUID HANDLING APPARATUS COMPRISING: LIQUID HOLDING MEANS HAVING ASIDE WALL DEFINING A LIQUID HOLDING SPACE AND MEANS DEFINING A BOTTOMOPENING; LIQUID TRANSFER MEANS HAVING A SUBMERSIBLE PUMP DISPOSED INSAID SPACE AND A MOTOR FOR DRIVING SAID PUMP EXTENDING DOWNWARDLYTHROUGH SAID OPENING; AND MEANS FOR SEALING SAID LIQUID TRANSFER MEANSTO SAID SIDE WALL INCLUDING FLANGE MEANS ON SAID LIQUID TRANSFER MEANSHAVING AN OUTER END EXTENDING CLOSELY ADJACENT BUT SPACED FROM SAID SIDEWALL, A RESILIENT SEAL MEMBER HAVING AN INNER GRIPPER PORTION SEALINGLYFITTED ON SAID FLANGE EDGE AND AN OUTER HOLLOW SEALING PORTIONCOMPRESSED SEALINGLY AGAINST SAID SIDE WALL, SAID SEAL MEMBER HAVINGOUTER CIRCUMFERENTIALLY EXTENDING RIBS FRICTIONALLY ENGAGING SAID SIDEWALL AND DEVELOPING THEREBETWEEN RELATIVELY HIGH CONTACT PRESSURE FROMRELATIVELY LOW STRESS FORCES DEVELOPED IN SAID HOLLOW OUTER PORTION OFTHE COMPRESSED SEAL MEMBER THEREBY TO MAINTAIN THE SEALING ENGAGEMENTAGAINST VIBRATION FORCES GENERATED BY OPERATION OF THE LIQUID TRANSFERMEANS.